Generally, electrical junction boxes are well known in the art. Such boxes are used in residential, industrial and commercial installations and in such instances, are of a relatively small size e.g. 4" in diameter and 1" to 3" in depth. They are normally placed in ceilings, walls, flooring, etc. to receive spliced conduits, valved conduits and other joints. Several examples of this type of junction box are known in the art as exemplified by U.S. Pat. Nos. 3,873,757 and 4,916,258, as well as Canadian Patent Nos. 765,295, 908,825, 528,475 and 1,185,668.
Junction boxes are also used in major installations in underground construction, where large cables are joined for high voltage lines. In such cases, the junction boxes are many times the size of the above type and may, for example, be 2' to 4' in diameter and 1' to 4' high. In the latter case, the construction and structural characteristics required for such junction boxes are significantly different than the small residential or like installations. Where such junction boxes are used exteriorly, they may be buried in the ground or mounted on a slab construction which is subsequently covered with earth, sand or the like. In addition to other factors, such junction boxes must obviously meet requirements for exposure to outdoor criteria e.g. water resistance, etc.
In the case of outdoor junction boxes, for large electrical installations, one possibility has been to construct a fixed enclosure of suitable material e.g. concrete, metal housings or the like. Apart from the cost effectiveness of such construction, there are also other considerations such as transportation, installation, etc. which add to the total economic factor for such apparatus.
It would be desirable if there could be provided a junction box structure and apparatus which can readily be mounted exteriorly, as well as one which can be useful for interior installation, and which can be manufactured in an economic and simple manner while at the same time providing a unit which can be readily secured in place under different locations and circumstances.
Conventionally the known junction boxes include clamps to fasten a cable therein entering the box. Typically, the boxes include "knockouts" to permit reception of a conduit within the box. Further, the known junction boxes comprise an electroconductive material which requires that electrical conduits be grounded thereto.